1. Field of the Invention
This invention relates to construction of a door in a motor vehicle, and more particularly to construction of a door suitable for use in a so-called flush-surface type motor vehicle, wherein the outer surface of a vehicle body and the surface of a door glass are made flush with each other.
2. Description of the Prior Art
The air resistance during running of a motor vehicle at high speed may reach more than twice the rolling resistance.
From this point of view, there has been proposed the so-called flush-surface type motor vehicle therein, to reduce the air resistance, the outer surface of the vehicle body and the surface of the door glass are made flush with each other.
A door in the flush-surface type motor vehicle as described above should be constructed such that the outer surface of the door glass and the outer surface of a door frame are made substantially flush with each other when the door glass is fully closed. However, the door glass is sucked out due to a difference in pressure between the interior and the exterior of a compartment during running of the motor vehicle at high speed. There is such a disadvantage that, when the door glass floats up outwardly from the outer surface of the door, so-called wind breaking sounds occur and the air resistance is increased during running.
To obviate the above-described disadvantages, for example, there has been proposed construction of a door in a motor car, wherein, as described in Japanese Utility Model Kokai (Laid-Open) No. 158321/81 (Refer to FIG. 7), a door glass piece 2 having a forward end 2A offset toward a compartment 3 and being of a substantially crank shape in cross-section is secured to an end portion 1A of a door glass 1 and the aforesaid forward end or slide portion 2A of this door glass piece 2 is slidably guided by a guide groove 5 on a door frame 4 in a direction of opening and closing of the door glass 1, whereby the outer surfaces of the door glass 1 and the door frame 4 are made substantially flush with each other and the door glass 1 is prevented from being sucked outwardly.
In the drawing, designated at 6 is a seal rubber disposed in the guide groove 5 and additionally functioning as a guide brought into contact with the forward end 2A of the door glass piece 2, 7 a center pillar, 8 a door weather strip, 9 a frame molding, and 10 a door panel welded to the door frame 4, respectively.
With the above-described construction of the door in a motor vehicle, the door glass 1 can be prevented from being considerably sucked outwardly. However, the seal rubber 6 for guiding the slide portion 1A of this door glass 1 in the vertical direction, having need of elastically contacting the door glass 1 when the door glass 1 is opened or closed, to seal between the door glass 1 and the door frame 4, may be elastically deformed in a direction of the thickness of the door glass, whereby the holding of the glass 1 when the door glass is fully closed, is weak in the direction of the thickness of the door glass, and therefore, there are presented such disadvantages that the performance of preventing the door glass 1 from being sucked out should not necessarily be satisfactory and the looseness tends to occur.
To obviate the above-described disadvantage, there may be proposed that the seal rubber 6 be replaced by a hard material to prevent the looseness of the door glass 1. However, such a proposal may cause new problems that the sealing function and the controllability of opening or closing of the door glass are impaired.
As described in West German Patent Application No. 2809721 for example (Refer to FIG. 8), a guide groove 5 integral with the door frame 4 is formed at the side of the compartment 3 of the end portion 1A of the door glass 1 and a slide piece 11 secured to the rear surface (on the side of the compartment 3) of the end portion 1A of the door glass 1 is raised and engaged with the guide groove 5 in a manner to be movable in the vertical direction, so that the looseness in the direction of the thickness of the door glass 1 may be reduced.
However, in this case, the sealing between the door glass 1 and the door frame 4 is conducted by a door glass weather strip 12 being in contact with corners of the end portion 1A of the door glass 1 and the outer peripheral surface 12A of this door glass weather strip 12 and the outer surface 4A of the door frame 4 on the side of the outer periphery of this door glass weather strip 12 are made substantially flush with the outer surface of the door glass 1, whereby a portion of the door glass weather strip 12, which contacts the outer surface of the door glass 1 is small and the width of the door glass weather strip 12 is made small to make the door frame portion look slim, whereby it is impossible to satisfactorily seal between the door glass 1 and the door frame 4. Moreover, there have been presented such disadvantages that, if contact pressure of the door glass weather strip 12 and the outer peripheral surface 12A are increased to enhance the sealing function, then the door glass 1 cannot perform smooth opening and closing operations and the flush surface is impared.